Depression is a common, serious and life threatening disorder, and its effects are persistent and debilitating.
The older antidepressants of the first generation, including imipramine and amitriptyline, have deleterious cardiovascular and anticholinergic side effects that can lead to serious toxicity in overdose and to poor patient compliance. The newer second generation drugs available from the mid-70's onwards, such as the atypical antidepressants and the inhibitors of serotonin reuptake (SSRI's), come with their own particular pattern of side effects which include sleep disturbances, gastrointestinal symptoms, sexual problems and anxiety. Lithium is plagued by a variety of adverse side effects, which often lead to poor compliance and subsequent relapse. The current alternatives to lithium, carbamazepine and valproate, are no more effective than lithium and carry the extra burden of haematological and hepatic toxicity respectively.